Sheet material pressing device

ABSTRACT

Two support structures, each having a plurality of downwardly extending, substantially equally spaced pressing members connected thereto, each with a hydraulic jack interposed therebetween, are provided extending over the entire width of a stack of sheet materials to be cut on both sides of the torch of an associated gas cutting apparatus. During a cutting operation, the support structures and those pressing members which are located within a predetermined range around the torch are operated incident to movement of the torch under the control of a numerical control system, thereby to hold the individual sheet materials in tight pressure contact with each other at portions where they are to be cut, as the torch moves.

[56] References Cited UNITED STATES PATENTS [72] inventors MasataroMuto;

Masaaki Yagasaki; Ken Hozumi, all of Nagasaki Japan 30,207

[21 Appl. No. [22] Filed Apr. 20, 1970 [45] Patented Jan. 11, 1972 [73]Assignee Mitsubishi J ukogyo Kabushiki Kaisha Tokyo, Japan ABSTRACT: Twosupport structures, each having a plurality of downwardly extending,substantially equally spaced pressing members connected thereto, eachwith a hydraulic jack interposed therebetween, are provided extendingover the entire width ofa stack of sheet materials to be cut on bothsides of the torch of an associated gas cutting apparatus. During acutting operation, the support structures and those [54] SHEET MATERIALPRESSING DEVICE 5 Chums 6 Drawing Figs pressing members which arelocated within a predetermined [52] US. 266/23 K, range around the torchare operated incident to movement of 148/9 the torch under the controlof a numerical control system, 823k 7/10 thereby to hold the individualsheet materials in tight pressure contact with each other at portionswhere they are to be cut, as the torch moves.

[50] Field ofSearch PATENTED m1 1 1972 SHEET 1 0F 3 FIG.I

PIC-5.5

INVENTO/PS MASATARO MUTO MASAAKI YAGASAKI KEN HOZUMI y ATTORNEYSPATENTEUJAM 1 I972 3.833896 SHEET? 0F 3 lA/VENTORS MASATARO MUTO MASAAKIYAGASAKI KEN HOZUMI M/JM ATTORNEYS memo JANi 1 i972 3533896 SHEET 3 0F 3Condition A ,S s i l T B2 Condition 8 503 Only B, is Moved l T B2 OnlT-is Moved l T B2 y Condition E 5 80* B' T 82 Only Tis Moved Only B isMoved Condition F 280 --i (Condition B) S +8o BI T B Only B, is MovedLS0 vk2 80 v- 5 80 Condmon 6 (Condition C) FIG.6

/N VE'N TORS MASATARO MUTO MASAAKI YAGASAKI KEN HOZUMI by %%M 4%ATTORNEYS SHEET MATERIAL PRESSING DEVICE The present invention relatesto a device for pressing sheet materials to be cut, which is adapted foruse with an apparatus for cutting out a plurality of members in the sameconfiguration from a stack of sheet materials by a gas cutting methodfor steel sheets operated under numerical control.

An automatic gas cutting method for steel sheets operated undernumerical control has already been put into practical use, and hascontributed to the reduction of scribing manhours and gas cuttingmanhours.

However, the apparatus heretofore used for practicing the method iscapable of cutting only one steel sheet at a time, and a separatefacility must be provided for pressing the sheet materials to be cut,for cutting a plurality of stacked steel sheets all at once.

In the construction of hulls, particularly those of large-sized shipsfor specialized use, it is becoming popular to use members of the sameconfiguration which have been cut out from steel sheet. Under thecircumstances, there has been an idea in the art that, if it is possibleto cut out these members all at once from a stack of steel sheets byemploying the abovedescribed automatic gas cutting method, it would be agreat contribution to a substantial reduction of manhours, animprovement of operational efficiency and a reduction of cost, in theship building industry, and efforts are being directed to this end.

A stacked-sheet gas cutting method has already been in use, though it isnot operable under numerical control. The most important factor instackcutting is that the stacked-sheet materials to be cut are tightlypressed against each other at the portions where they are to be cut,which portions shift successively incident to the movement of a torchover the surface of said stack. In the conventional stacked-sheet gascutting method, such problem remains unsolved and it is impossible tohold the steel sheets in complete pressure contact with each other atthe central portions thereof. As a result, the conventional method hasthe disadvantages that well out edges cannot be obtained and hence adesired configuration cannot be obtained precisely, and that a largeamount of labor is required since the cutting operation is notautomated.

There has also been proposed recently a method for automatically cuttingthe edges of steel sheets straight by means of p a gas torch. However,the application of this method is limited to only rectilinear cutting ofthe steel sheet edges, because the problem of holding the centralportions of the sheet materials in pressure contact with each other hasnot been solved in this method either. p p

Further, the above-mentioned prior art gas cutting method for steelsheets, operable under numerical control, is not adapted for use instack cutting apparatus, because when steel sheets to be cut are stackedin the apparatus, the condition at the central portion of the steelsheet stack is exactly the same as that in the conventionalstack-cutting apparatus for steel sheets.

However, if the condition of intimate contact between each other, of thestacked-sheets materials to be cut, is obtained at the portions oppositeto the torch as the torch moves over the sheet material stack, thestack-cutting of the steel sheets will be attained, completely, evenwith the prior art gas cutting apparatus.

Based on such concept, the present invention aims to provide a sheetmaterial pressing device which is adapted for use with an automatic gascutting apparatus for stacked-sheet materials and which is capable ofholding the portions to be cut, of the stacked-sheet materials, alwaysin pressure contact with each other, no matter how the cutting torch isoperated to cut the sheet materials. The sheet material pressing deviceaccording to the instant invention comprises two support structuresextending over the entire width of the sheet materials to be cut on boththe front and back, or the left and right, sides of the torch of anassociated gas cutting apparatus carried on the support structure of gascutting apparatus and controllably operated, these two supportstructures being stopped and moved repeatedly individually; and aplurality of substantially equally spaced sheet material pressingmembers mounted on each of the support structures along the lengththereof, each with a hydraulic jack interposed therebetween, andextending downwardly from the support structure, only those sheetmaterial pressing members which are located within a predetermined rangearound the torch being actuated incident to movement of the torch.

With the device of the invention, the portion of the sheet materialstack to be cut in the vicinity of the torch of the gas cuttingapparatus is always pressed by the sheet material pressing members.Therefore, the individual sheet materials can be held in pressurecontact with each other positively at such portion and the gas cuttingapparatus can fully achieve its function as a stack-gas cuttingapparatus, enabling a plurality of sheet members of the sameconfiguration to be obtained all at once, with a well cut edge.

For an understanding of the principles of the invention, reference ismade to the following description of a typical embodiment thereof asillustrated in the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a fragmentary perspectiveview of the sheet material pressing device according to the presentinvention;

FIG. 2 is a fragmentary front elevation of the device;

FIGS. 3 and 4 are cross-sectional views taken on the respective linesIII-III and IVIV of FIG. 2;

FIG. 5 is a diagram illustrating the operation of the pressing membersof the device of this invention relative to the torch and FIG. 6 is adiagram illustrating the operation of the support structures of thedevice of this invention relative to the torch.

DESCRIPTION OF I-IE PREFERRED EMBODIMENT Referring first to FIGS. 1through 4 of the drawings, reference numeral 1 designates alattice-shaped mounting bed for mounting sheet materials (steel sheets)to be cut thereon, and 3 designates a gas cutter support structureextending over mounting bed 1 and movable longitudinally of the mountingbed as indicated by the arrows, with wheels 4, 4 at the opposite endsthereof rolling on guide rails 5 provided along the oppositelongitudinal edges of the mounting bed.

Reference numeral6 designates a gas cutter mounted on the gas cuttersupport structure 3 in such a manner as to be movable transversely ofthe mounting bed 1, and having a torch 7 connected to the centerthereof.

The above-described construction of a gas cutting apparatus is alreadyknown, and the movement of the gas cutter support structure 3 relativet0 the mounting bed I and the movement of the gas cutter relative to thesupport structure 3 are respectively effected by prime movers providedat suitable locations, which are not apparent in the Figures. Needlessto say, the amounts of movement of these members are automaticallycontrolled by a numerical control system. Thus, it will be seen that thegas cutter 6 with the torch 7 connected thereto is movable in twodirections perpendicular to each other, i.e., in the directionslongitudinally and transversely of the stack of sheet materials 2mounted on the mounting bed 1, to locate the torch 7 in any desiredposition on the stack of sheet materials. Reference numerals 8, 8designate structures for pressing members to be described later. Thesesupport structures are provided on both sides of the torch 7 and extendparallel to each other transversely over the entire width of the sheetmaterials 2, with a predetermined space therebetween. Each of thesupport structures 8, 8 is provided at the opposite ends thereof withwheels 9, 9 and is movable in the longitudinal direction of the mountingbed 1, with wheels 9, 9 rolling in rails 10, 10 which are provided alongthe opposite longitudinal edges of the mounting bed.

The movement of the pressing member support structures 8, 8 is effectedby a conventional driving means not shown and the amount of the movementis controlled by the numerical control system. Namely, the supportstructures 8, 8 move and stop repeatedly, following the movement of thetorch 7 for cutting operation, under the control of the numericalcontrol system. Reference numeral 11 designates a plurality of pressingmembers, mentioned above, which are connected to each of the supportstructures 8, 8 over the entire length thereof, with a predeterminedspace between each other and each with a hydraulic jack 12 interposedbetween it and said support structure, and which extend downwardly fromthe support structure with the lower ends thereof lying in one and sameplane. Each of these pressing members is actuated by the associatedhydraulic jack when pressure fluid is supplied to the hydraulic jack.The pressing members 11 are controlled by the numerical control systemin such a manner that, as the torch 7 moves, only those pressing memberswhich are located in the vicinity of torch 7 are actuated.

The apparatus constructed as described above will operate in thefollowing manner:

First of all, a desired number of sheet materials 2 to be cut arestacked on the mounting bed 1 and the torch 7 is positioned at a cuttingstarting point on the stack of sheet materials 2 by driving the supportstructure 3, carrying the gas cutter 6 thereon, under the control of thenumerical control system. At the same time, the support structures 8, 8are operated so as to locate them at a predetermined distance from eachother, with the torch 7 interposed therebetween and a plurality of e.g.,four of, the pressing members 11 are lowered to press the stack of sheetmaterials 2 by feeding hydraulic fluid into the hydraulic jacks 12 ofrespective pressing members, all under the control of the numericalcontrol system.

The reaction of the pressure of the pressing members 11 is taken by theguide rails l0, 10 through the wheels 9, 9 at the opposite ends of thesupport structures 8, 8 and thus the stack of the sheet materials 2 ispressed from the top, with the in dividual sheet materials being held inpressure contact with each other with sufficient force.

Under such condition, the gas cutter support structure 3 and the gascutter 6 are moved longitudinally and transversely of the mounting bed1, either concurrently or independently, under the control of thenumerical control system, so that the torch 7 carried by the gas cutter6 moves while cutting the sheet materials. Thus, the gas cutting of thesheet materials 2 is carried out automatically.

During the cutting operation, the support structures 8, 8 are operatedalternately intermittently and the fluid supply to the hydraulic jacks12 is shifted, incident to the movement of torch 7, so as to press thestack of sheet materials 2 by a plurality of pressing members 11 in thevicinity of the torch 7.

The operations of the support structures 8, 8 and the pressing members11 carried thereby will be practically explained with reference to FIGS.5 and 6.

In FIGS. 5 and 6, the gas cutter support structure 3 is represented bysymbol B, the torch 7 by symbol T, the support structures 8, 8 bysymbols B, and B respectively, and the hydraulic jacks 12 (the pressingmembers 11) connected to the respective support structures 8, 8 bysymbols J,, J J J and J and symbols J,, J J J, and J respectively. Whenthe torch T is in the position shown in FIG. 4, the support structures8,, B are located at equal distances S from the gas cutter supportstructure B, and only the hydraulic jacks J J and J,, J, are actuated topress the stack ofsheet materials 2.

This condition lasts until the torch T reaches the point@or uponmovement in the direction indicated by the respective arrows. However,when the torch T reaches the pointor upon further movement, thehydraulic jacks J, and J, are actuated either concurrently orindependently to press the stack of sheet materials 2, whereas thehydraulic jacks .l and J are released.

In the manner described, the hydraulic jacks J and J, are actuated andthe hydraulic jacks J and J are released, as the torch T further move tothe left in the direction of- @.On the other hand, when the torch Tmoves in the direction of @a (a), i.e.,in a directiogtoapproach thesupport structure 8,, the

operation of he support structures 8,, B as shown in FIG. 6 is added tothe above-described operation of FIG. 5.

In this case, the support structures B,, B as shown are moved with allof the hydraulic jacks 1,, J and J,, J on the respective supportstructures being in the released state. Therefore, it will be understoodthat it is undesirable to move the support structures B, and Bconcurrently and the phases of movement of said support structures mustbe displaced relative to each other.

Referring to FIG. 6, there is shown the relative positions of the torchT and the support structures B, and B In the diagram ofFIG. 6,

S the standard intervals between the support structures B, and B and thetorch T the distance which the support structures B, and B move uponrelease of the hydraulic jacks S 8 the minimum allowable intervalbetween the torch T and the support structures B, and B S +8 8 /2) themaximum allowable interval between the torch T, and the supportstructures B, and B Namely, on each movement of the torch T by adistance (d /2a), the support structures B, and B move alternately andtake the relative positions with respect to the torch as shown in FIG. 6respectively, under the conditions set forth below:

a. Condition A B, and B are held stationary at distances S from T.

b. Condition B ..T is moved and spaced from B, by the minimum allowabledistance S,,6

0. Condition C ..B, is moved and spaced from T by a distance S,,.

d. Condition is moved by a distance (5 /2) and spaced from B by themaximum allowable distance S,,+8 +(6 0/ e. Condition E .B is moved by adistance 8,, and spaced from T by a distance S +(6 /2).

f. Condition F (Condition B) ..T is moved by a distance (S /2a) andspaced from B, by a distance S,,8

g. Condition B (Condition C) ..B, is moved and spaced from T by adistance S Thus, the support structures B, and B are stopped and movedregularly and repeatedly incident to the movement of torch T. In thiscase, the period from the time when a support structure B, or B is movedby a distance 8 upon having the hydraulic jacks J,, J or J,, J released,and brought to a halt, to the time when hydraulic jacks J,, J, or J,, Jare actuated again, is so selected as to fall within the period in whichthe torch T moves a distance (6 /2) while cutting the sheet materials.

Although the operations of the support structures 8,, B and theassociated hydraulic jacks 1,, J and J,, J have been explained withreference to the case wherein the torch T moved in the direction of thearroworin FIG. 5, it should be understood that they operate in the samemanner when the torch T moves to the right as viewed in FIG. 5 or towardthe support structure 8,.

The support structure 3 and the gas cutter 6 mounted thereon are movedsuccessively under the control of the numerical control system, whilecutting the stack of sheet materials 2 by the torch 7, as describedabove, and during the cutting operation, the stack of sheet materials 2is constantly pressed by a plurality of the pressing members 11 atportions which are spaced predetermined distances from the torch 7.Therefore, the individual sheet materials 2 of the stack are held inpressure contact with each other with sufficient force at the portionswhere they are to be cut out and as a result, a reliable, accuratecutting by the torch 7 can be achieved.

It is particularly to be noted that, since according to the presentinvention, it is only necessary to movably mount the two supportstructures 8, 8 over the entire width of the sheet materials 2 to be cutand connect a plurality of the pressing members to each of the supportstructures 8, 8 to extend downwardly therefrom, each with the hydraulicjack l2 interposed therebetween, the device of the invention is verysimple in structure and can be produced at a low cost.

It is also to be noted that, in carrying out a cutting operation by acutting apparatus which is provided with the device of this invention,the sheet materials 2 to be cut are always pressed together tightly byonly those pressing members 11 which encircle the torch 7 and,therefore, only a small power nourcc is sufficient to operate thehydraulic jacks 12.

A further advantage of the device of this invention is that, since thesupport structure 8 is not allowed to move while any one of the pressingmembers 11 is in action, there is no possibility that the operation ofthe gas cutter 6 is adversely affected by a vibration of the supportstructure 8 which would otherwise occur during movement of a supportstructure, and hence a high-precise gas cutting can be attained.

In short, according to the present invention the pressing devicecomprises two support structures extending over the entire width of thesheet materials to be cut on both the front and back, or the left andright sides, of the torch of an associated gas cutting apparatus carriedon the support structure of the gas cutting apparatus and controllablyoperated, the two support structures being stopped and moved repeatedlyindividually incident to movement of said torch; and a plurality ofpressing members connected to each of the support structures insubstantially equally spaced relation, each with a hydraulic jackinterposed therebetween, and extending downwardly from said supportstructure, only those of said pressing members which are located withina predetermined range around said torch being actuated incident tomovement of said torch to press the sheet materials. Therefore, thedevice is simple in both construction and operation, and is capable ofholding a plurality of stacked-sheet materials to be cut in pressurecontact with each other very effectively, during cutting operation ofasteel sheet gas cutting apparatus. By employing the pressing device ofthis invention, efficient, highly precise, automatic stack cutting by agas cutting apparatus becomes possible, which is a great contribution tothe ship building industry in respect of reduction in working manhours.

What is claimed is:

1. A pressing device, for compressing a stack of sheet material, stackedupon a stack support, during cutting of the stacked-sheet material bycutting apparatus including a cutting tool directing a hot gaseouscutting medium against the stacked-sheet material and controllablymoved, in a predetermined cutting pattern, over the stack, said pressingdevice comprising, in combination, two support structures extending overthe entire width of the stack on opposite sides of said tool; meansmounting said support structures for individual positional adjustmentover the stack in accordance with the controlled movement of said toolover the stack; a plurality of pressing members carried by each supportstructure in substantially equally spaced relation therealong andextending downwardly toward the stack; and means operable, during suchcontrolled movement of said tool over the stack, to press only thosepressing members within a predetermined range around said tool againstthe stack, to firmly compress the sheet material during cutting of thestack thereof.

2. A pressing device, as claimed in claim 1, including means coupled tosaid support structures and absorbing the reaction force due to pressingof said pressing members against the stack.

3. A pressing device, as claimed in claim 1, in which said last namedmeans comprises respective jacks interposed between each pressing memberand the associated support structure.

4. A pressing device, as claimed in claim 3, in which said jacks arehydraulic jacks.

5. A pressing device, as claimed in claim 1, in which said mountingmeans comprises rails extending along each side of the stack and wheelson said support structures engaged in said rails; said rails restrainingsaid wheels against upward movement when said pressing members arepressed against the stack.

1. A pressing device, for compressing a stack of sheet material, stackedupon a stack support, during cutting of the stacked-sheet material bycutting apparatus including a cutting tool directing a hot gaseouscutting medium against the stacked-sheet material and controllablymoved, in a predetermined cutting pattern, over the stack, said pressingdevice comprising, in combination, two support structures extending overthe entire width of the stack on opposite sides of said tool; meansmounting said support structures for individual positional adjustmentover the stack in accordance with the controlled movement of said toolover the stack; a plurality of pressing members carried by each supportstructure in substantially equally spaced relation therealong andextending downwardly toward the stack; and means operable, during suchcontrolled movement of said tool over the stack, to press only thosepressing members within a predetermined range around said tool againstthe stack, to firmly compress the sheet material during cutting of thestack thereof.
 2. A pressing device, as claimed in claim 1, includingmeans coupled to said support structures and absorbing the reactionforce due to pressing of said pressing members against the stack.
 3. Apressing device, as claimed in claim 1, in which said last named meanscomprises respective jacks interposed between each pressing member andthe associated support structure.
 4. A pressing device, as claimed inclaim 3, in which said jacks are hydraulic jacks.
 5. A pressing device,as claimed in claim 1, in which said mounting means comprises railsextending along each side of the stack and wheels on said supportstructures engaged in said rails; said rails restraining said wheelsagainst upward movement when said pressing members are pressed againstthe stack.